develops from develops from adjacent to adjacent to endocardial cushion right cardiac atrium heart left ventricle cardiac septum atrioventricular septum UBERON:0005989 membranous atrioventricular septum The wall of the heart that separates the right atrium and left ventricle; and is located just above the septal cusp of the tricuspid valve. EMAPA:37431 Wikipedia:Atrioventricular_septum FMA:7136 SCTID:280151006 neural crest-derived structure